"From the moment we closed the Starwood merger in late 2016, the revitalization of Sheraton has been a top priority for our company," said Arne Sorenson, president and CEO of Marriott International. "We knew that the way to restore this incredible brand was [through] focus and collaboration with our hotel owners."

According to Marriott, Sheraton property owners in the U.S. have already committed $500 million to renovations at their hotels. Globally, about a quarter of Sheraton owners have signed on to renovation projects, with some already underway.

"We wanted to build on Sheraton's rich legacy of sitting at the heart of communities across the globe, but also to create a differentiated positioning and compelling proposition for our owners. With our Sheraton transformation plan, we've put together all of the pieces of the equation to work cooperatively with our owners to set this iconic brand on a new, disciplined and successful path. We are ready, our vision is clear and the energy is robust for Sheraton," said Sorenson.

Sheraton showcased its plans this week at the NYU International Hospitality Industry Investment Conference in New York City, allowing investors to experience the layouts firsthand with a 4,200-square-foot display. Marriott is building on the brand's roots as a gathering place for locals and guests alike, and focusing on socialization, productivity and personalization with new designs. Collaboration and technology are major themes for the revamped hotels' public spaces.

"Marriott International is well positioned to deliver a comprehensive strategy for Sheraton's brand transformation, and we already have great momentum," said Tina Edmundson, Marriott's global brand officer. "This is the first time in years that the brand has been above competitive benchmarks in both rate and occupancy. We have improved brand standards, increased group bookings and have ramped up our business engine over the last year as a first step in a multiphase, multiyear plan, leveraging our experience in revitalizing lodging brands."

Marriott executives have recent experience updating a flagship brand, having embarked on a similar project in 2013 for the Marriott Hotels flag. In collaboration with hotel owners, the company redesigned the guest rooms and MClub Lounge. Renovated Marriott properties have seen average market-share gains of 9 percent, and "intend to recommend" scores from customers in those hotels are eight points higher, on average, than for their nonrenovated Marriott counterparts.

Marriott already has begun culling the Sheraton herd: Since acquiring the brand in 2016, 6,000 rooms have been dropped from the brand, and 2,000 additional rooms should be gone by the end of this year. Meanwhile, the company has signed 5,000 rooms to join the brand's portfolio. Market share has grown for the first time in years, and intend-to-recommend scores are up two points year-over-year.

There are currently 450 Sheraton properties in operation worldwide and an additional 80 in the pipeline. Marriott expects the brand to be in 90 countries by 2020.